pre-mRNA

Pre-mRNA, or precursor messenger RNA, is the initial version of RNA produced inside a cell's nucleus from a gene. Think of it as a rough draft that contains both the useful instructions (exons) and unnecessary or intermediate segments (introns). Before this RNA can be used to make proteins, it undergoes processing to remove introns and combine exons, resulting in mature mRNA. This mature mRNA then exits the nucleus and guides the cell’s machinery to build specific proteins, enabling biological functions and processes. Pre-mRNA thus serves as an essential intermediate step in gene expression.